1. Field of the Invention
The present invention relates to a method for joining a structure made of fiber-reinforced plastics to a metal fixture. This invention, more specifically relates to rotatable elements, such as to wheels, handwheels or the like made by said method.
2. Discussion of the Background
Wheels, such as hand-wheels or steering wheels have heretofore been manufactured by a method which comprises curing a fiber-reinforced plastic structure in a shape conforming to the shape of the wheel being produced, then subjecting the cured structure to a prescribed aftertreatment (e.g., a mechanical treatment), fitting into the structure a metallic insert for attachment to a rotary shaft, and bonding the fiber-reinforced plastic structure to the metallic insert with an adhesive agent (e.g., a thermosetting resin). This method, however, suffers varied drawbacks. The aftertreatment tends to break the reinforcing fibers, and often causes strength degradation in the fiber-reinforced plastlc structure. Further since this method of bonding relies on the use of an adhesive agent, the strength of bonding between the fiber-reinforced plastic structure and the metallic insert is limited to the bonding strength of the adhesive agent used. On exposure to repeated abrupt changes of temperature, the fiber-reinforced plastic structure and the metallic insert may separate from each other. Thus, this method has among other disadvantages, the disadvantage of insufficient bonding reliability.
British Patent No. GB 2 004 835 A discloses a resin-impregnated fiber strand obtained by impregnating continuous long-staple fibers such as, for example, glass fibers, carbon fibers, etc., with resin such as a polyester resin. This material has begun to find utility as backbone materials in various lattice structures, such as pylons, aeroplane fuselages, bridge grid structures, etc.
Accordingly, there continues to exist a need for a method for manufacturing wheels, hand-wheels or the like which are resistant to deterioration and breakage and have enhanced reliability. This method should also not inflict breakage of the reinforcing fibers.